1. Field of the Invention
The present invention relates to a pair of glasses that may be adjusted automatically to improve the quality of vision while the user accommodating from far seeing to near seeing.
2. Description of the Related Art
Eyeglasses is used for correction of refractive error of user. The correct eyeglasses is determined by the correct power of the glasses and the centration of the glasses with the vision axis as well as the correct angle of the glasses with the visual axis.
As shown in FIGS. 1 and 3, when the user puts on a pair of conventional glasses to have a far view, the viewing line xe2x80x9caxe2x80x9d and the lens 100 form an included angle equal 90 degree.
As shown in FIGS. 2 and 4, when the user bows his head for reading or writing to have a near view, his eyes are convergent. The viewing line axe2x80x2 is deflected from the center of the lens 100, thereby forming an error value equal to angle xcex8 as shown in FIG. 4. The deflection distance between the viewing line axe2x80x2 and the center of the lens 100 is equal to xe2x80x9c1xe2x80x9d. Thus, when the user has a near view, he easily feels uncomfortable due to the error of angle and the error of deflection of the center. To the best of our knowledge the classical eyeglasses never considered to compensate the angle of convergence and center shift while user accommodating from far to near. In this invention we resolved the problem induced by error of glasses while accommodating from far to near.
Few patents in USA have mentioned an adjustable eyeglasses. In U.S. Pat. No. 5,485,227 by me disclose a light transmission adjustable spectacle. In U.S. Pat. No. 5,133,595 to Gutbrod et al. disclose a length adjustable spectacle temple. In U.S. Pat. No. Des. 308,978 to Anger disclose an adjustable eyeglasses which can adjust the width of the frame and the length of the temple. In U.S. Pat. No. 5,987,640 to Ryder disclose a visor and eyeshield assembly which can flip the visor up or down for using or not using the visor. All the above mentioned patents are different from the present invention.
The primary objective of the present invention is to provide a pair of glasses that may be adjusted automatically. The main frame is formed with a slide slot. A slide fixed on the lens frame may slide in the slide slot, thereby automatically or manually compensating the deflection of the center of the lens when a user bows his head for reading or writing such that the center of the lens after calibration is still located on the user""s viewing line, and so that the user may have a clear and comfort near vision.
Another objective of the present invention is to provide a pair of glasses that may be adjusted automatically. The main frame includes a bridge having two sides each respectively provided with a housing which is formed with a slide channel. The lens frame has a slide bar that may be extended into the slide channel of the housing. Displacement of the slide bar compensates the deflection of the center of the lens such that the center of the lens after calibration is still located on the user""s viewing line.
A further objective of the present invention is to provide a pair of glasses that may be adjusted automatically. A returning elastic plate is mounted between the lens frame and the main frame. The returning elastic plate may automatically force the lens frame to return to its original position, so that the user may have a good horizontal view or far view.
In accordance with one aspect of the present invention, there is provided a pair of glasses that may be adjusted automatically, comprising: a main frame having two side leg seats each respectively formed with a slide slot into which a slide may extend, the slide connected with a lens frame, wherein the slide may displace in the slide slot of the main frame to drive the lens frame to move relative to the main frame, thereby compensating a deflection of a center of a lens when a user bows his head for reading or writing such that the center of the lens after calibration is still located on a viewing line, and so that the user may have a clear near view.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.